The present invention relates to a device with which it is possible to replace a first respiratory probe, for example a used one already in place in the trachea of a patient, with a second respiratory probe, for example a new one, external to said patient.
It is known that patients requiring respiratory assistance are connected to an appropriate gas source, for example linked up to an artificial respirator.
The patient is provided with a probe, in his trachea, and this probe is connected to said respiratory gas source via at least one supply conduit.
It is also known that for reasons of hygiene or for technical reasons, such a probe has to be replaced from time to time, for example because of the deterioration of some of its components (positioning balloon), or else in order to replace the probe in situ with a probe of a different type. The positioning of a replacement probe is generally a complex and painful operation, because very often the surface of the trachea is swollen and its diameter is reduced.
Moreover, the procedure of replacing one probe with another one necessitates interruption of the respiratory assistance for a relatively long period of time, and this is prejudicial to the health of the patient.
The object of the present invention is to overcome these disadvantages.
To this end, according to the invention, the device for replacing a first respiratory probe, already in place in the trachea of a patient, with a second respiratory probe external to said patient, said first probe being supplied with respiratory assistance gas via at least one main supply conduit, is distinguished by the fact that:
it is tubular, flexible and elongate and has at least one distal orifice and at least one proximal orifice;
it can be introduced into said first and second respiratory probes, which are able to slide on said device; and
it can be connected via its proximal orifice to an auxiliary conduit for supplying respiratory gas at a higher pressure than that of the main supply conduit.
Moreover, it is advantageous that said respiratory probes can slide on said auxiliary supply conduit.
Thus, by means of the present invention, the procedure for replacing a first respiratory probe, already in place in the trachea of a patient, with a second respiratory probe external to said patient, said first probe being supplied with respiratory assistance gas via at least one main supply conduit connected to said first probe, can consist in the sequence of the following steps:
a) said main supply conduit is disconnected from said first respiratory probe and said flexible and elongate tubular device having at least one distal orifice and at least one proximal orifice is introduced into said first respiratory probe;
b) said flexible and elongate tubular device is connected via its proximal orifice to said auxiliary conduit for supplying respiratory gas at a higher pressure than that of the main supply conduit;
c) said first probe is withdrawn from said trachea by sliding it along said flexible and elongate tubular device kept in place in the trachea, and, if appropriate, along said auxiliary supply conduit;
d) said auxiliary supply conduit is disconnected from said flexible and elongate tubular device and said first probe is removed;
e) said second probe is passed onto said auxiliary supply conduit, or, if appropriate, onto said flexible and elongate tubular device, and said flexible and elongate tubular device is connected via its proximal orifice to said auxiliary supply conduit; and
f) said second probe is slid over said flexible and elongate tubular device until it is correctly positioned in the trachea.
It is therefore possible, by means of the present invention, to minimize the interruption in respiratory assistance since each disconnection of the supply conduits can be of short duration. Moreover, said flexible and elongate tubular device serves as a guide for withdrawing the first respiratory probe and for positioning the second of said probes, which fact facilitates the change of probes and reduces the operating procedure for doing so.
It will be noted, furthermore, that said flexible and elongate tubular device can serve as a guide during the earlier positioning of said first probe. After step f), it could also remain in place in said second probe in order to dispense the respiratory assistance gas to the patient.
However, according to one advantageous embodiment of the procedure described above, after above mentioned step f), the following two additional successive steps are implemented:
g) said auxiliary supply conduit is disconnected from said flexible and elongate tubular device, and said flexible and elongate tubular device is withdrawn from said second probe; and
h) said main supply conduit is connected to said second probe.
The device according to the present invention can include:
a central tubular core having a proximal orifice which can be connected to said auxiliary supply conduit and a distal orifice for dispensing said respiratory gas; and
a tubular sheath surrounding said tubular core with clearance and made integral with said central tubular core.
At its distal end, said tubular sheath preferably projects from the distal end of said tubular core.
Thus, said central tubular core is protected by said tubular sheath so that the distal orifice of said tubular core cannot be blocked, for example by mucus. For similar reasons, in a first embodiment, said tubular sheath is provided with orifices in its side wall and is closed, at its distal end, by a closure wall, if appropriate provided with one or more orifices.
The length of said device is advantageously such that when it is positioned in the trachea of said patient, said tubular sheath protrudes from the patient""s mouth, and that part of said sheath external to said patient is also provided with orifices.
Thus, a dangerous overpressure cannot occur in the trachea of the patient since the respiratory assistance gas is able to escape via the orifices of the sheath external to the patient.
In a second embodiment of said device according to the present invention, the tubular sheath is open at its distal end, and said clearance, between the central core and the sheath, is connected to a source of pressurized fluid, for example a source of water. It is thus possible to humidify the trachea and prevent the latter from drying under the action of the respiratory assistance gas. Of course, any other fluid (medication for example) could be conveyed in this way via said clearance. Moreover, it is possible to provide auxiliary fluid conduits between said sheath and said core, and also, if appropriate, within the wall thickness of these.
Moreover, to avoid the core and the sheath being crushed at the sites of the bends of the device (and thus an interruption in respiratory assistance), and in order to centre said device in relation to the trachea walls, it is advantageous that said device, irrespective of its embodiment, includes an outer helical spring surrounding said tubular sheath. Such a spring can be made of a material with shape memory (Nitinol, for example) and can assume its helical shape only when it is subjected to the temperature conditions prevailing in the trachea.
According to a third embodiment of said device according to the present invention, said central tubular core and said tubular sheath have a helical shape.
In yet another embodiment, the device according to the invention includes an elongate body, made of synthetic material for example, provided with a plurality of longitudinal channels, one of which can be connected to an auxiliary supply conduit for respiratory gas, at its proximal end. In another of said longitudinal channels it is possible to introduce a deformable wire in order to impart its shape, for example its helical shape, to said device.